<!DOCTYPE html>
<html>
<head>
	<meta charset="utf-8">
	<title>jquery</title>
</head>
<body>
<div id='app'>
	<div class="item item1">11</div>
	<div class="item item2">22</div>
	<div class="item item3">33</div>
</div>
<script src="https://code.jquery.com/jquery-3.6.0.js"></script>
<script src="./jQuery.js"></script>
<script>
console.log($(".item"));
console.log($());
</script>
<script>
console.log('--------------------------');
</script>
<script>
console.log($$(".item"));
console.log($$());
</script>
</body>
</html>